That was the correct thing to do. Considering how many npm packages the average project consumes, having even a single line of advertising for each would make npm a pain in the ass to use, and people would be looking for ways to block the ads.
Clearly, you didn't read the article from the original author. Ads were deduplicated, so only a single ad was shown, even if 500 deps used the funding dependency.
That’s a big _if_. Until now, each package with ads have rolled their own, and since there’s probably more money to be had that way, there’s no reason that would not continue.